Device having a table fitted with two sliding elements,for the quick finding of main formulae related to geometric entities

ABSTRACT

THE DEVICE FOR THE QUICK FINDING OF MAIN FORMALAE RELATED TO GEOMETRIC ENTITIES COMPRISES A STATIONARY ELEMENT AND TWO SLIDING COMPONENTS. THE STATIONARY ELEMENT CONSISTS OF A RECTANGULAR PLATE, ON EITHER SIDE OF WHICH TWO GUIDES ARE FORMED. SLIDINGLY FITTED BETWEEN SAID TWO GUIDES IS A MOVABLE COMPONENT, CONSISTING OF A RECTANGULAR PLATE MADE OF AN OPAQUE MATERIAL, AND FORMED WITH TWO SYMMETRICALLY LOCATED, QUADRANGULAR WINDOWS, BEING THE DEPICTIONS OF GEOMETRIC ENTITIES REPRODUCED ON BOTH SIDES OF THE STATIONARY ELEMENT, NEAR THE UPPER AND LOWER EDGES THEREOF, WHILE THE RELATED RESOLUTIVE FORMALAE ARE PRINTED OR ENGRAGED ADJACENT EACH DEPICTED GEOMETRIC ENTITY.

G. IAlA 3,584,399 DEVICE HAVING A TABLE FITTED WITH TWO SLIDING ELEMENTS, FOR

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QUWQZ BED United States Patent 3,584,399 DEVICE HAVING A TABLE FITTED WITH TWO SLIDING ELEMENTS, FOR THE QUICK FINDING 0F MAIN FORMULAE RELATED TO GEO- METRIC ENTITIES Giuseppe Iaia, Via della Rotonda 69, Augusta, Siracusa, Italy Filed June 4, 1969, Ser. No. 830,361 Claims priority, application Italy, June 25, 1968, 130,567 Int. Cl. G09b N16 US. Cl. 35-34 2 Claims ABSTRACT OF THE DISCLOSURE The device for the quick finding of main formulae related to geometric entities comprises a stationary element and two sliding components. The stationary element consists of a rectangular plate, on either side of which two guides are formed. Slidingly fitted between said two guides is a movable component, consisting of a rectangular plate made of an opaque material, and formed with two symmetrically located, quadrangular windows, being the depictions of geometric entities reproduced on both sides of the stationary element, near the upper and lower edges thereof, while the related resolutive formulae are printed or engraved adjacent each depicted geometric entity.

This invention concerns a device, having a table fitted with two sliding elements, for quickly finding the main formulae pertaining to geometric entities (plane and solid figures).

It is not easy to keep in mind the formulae for the solution of geometric problems, above all when they concern uncommon geometric figures; moreover, when problems of such kind are to be solved, the required handbook is not always available. At any rate, even when such handbooks are available, the search for the required resolutive formulae is time-consuming and irksome.

The purpose of this invention is the provision of a small sized device, that can be carried in the users pocket, and by which all formulae for the solution of the problems related to the considered geometric entity can be found in an unusually easy and convenient manner and without possibility of errors.

The device according to this invention will be best understood from a consideration of the following, detailed description of a preferred embodiment thereof, as shown in the accompanying drawing, wherein:

FIGS. 1 and 2 are front views of opposite sides (i.e. front and rear sides) of the device according to the invention.

FIG. 3 is a section of device taken on the line AA of FIG. 1. 7

FIGS. 4 and 5 are front views of sliders of the device as shown in FIGS. 1 and 2.

FIGS. 6 and 7 respectively are a section of a slider taken on the line B-B of FIG. 4, and a section of the opposite slider, taken on the line C-C of FIG. 5.

The device of this invention, and that is shown in the FIGS. 1 to 3 inclusive, consists of a stationary component, and of two further components slidingly fitted thereon. Said stationary component is a rigid, rectangular plate 1, having four guides 23 and 45 respectively, formed along opposite sides thereof, in parallel relation with the adjacent side edge of plate 1. Such guides are designed to allow two slides, denoted by the reference numerals 6 and 7 respectively, to be endwise shifted therein.

Engraved, printed or otherwise represented on one side of the stationary element, adjacent both edges thereof 3,584,399 Patented June 15, 1971 as shown in FIG. 1are the plane geometric figures, preferably framed, as depicted in that figure, and umformly spaced from each other. In the considered example such figures are: a square, a rectangle, a triangle, a rhombus, a trapezium, a pentagon, a hexagon, a heptagon, an octagon, a nonagon, a decagon, a dodecagon, a circle and an annulus.

Also engraved, printed or otherwise represented near both edges of the opposite side of plate l-as shown in FIG. 2are the solid geometric bodies, preferably framed, as depicted in that figure and uniformly spaced from each other. In the considered example such bodies are: a sphere, an octahedron, a hexahedron (or cube), a tetrahedron, a segment of a sphere, a spherical sector, a hemisphere, a triangular prism, a parallelepipedon, a regular pyramid, a truncated pyramid, another regular pyramid, a truncated cone and a right cylinder.

Engraved or printed on the plate 1, below each depiction of geometric entity, are the formulae by which the problems involving the same geometric entity can be solved. The space occupied by these formulae extends between the longitudinal midline of the stationary plate, and the lines by which the depiction-containing frames are laterally delimited.

The slides 6 and 7, which are substantially similar one another, as shown in FIGS. 4 to 7, consist of rectangular plates, made of a non-transparent material, and having their edges in parallel relation with the undercut major sides.

Two rectangular windows are formed in each slide, and more precisely the windows 8 and 9 are formed in the slide 6, while the windows 10 and 11 are formed in the slide 7.

The windows, which are preferably formed symmetrically in respect of the longitudinal and transverse midlines that intersect each other at the midpoints thereof, are such as to leave in View only those formulae that concern a given geometric entity.

Thus, e.g., in the FIG. 1, by the windows 8 and 9 are left uncovered, and thus in view, only the formulae (symbolized respectively by a row of reference letters U and by a row of reference letters Z) that allow the solution of problems concerned with the square, as depicted in the frame 14, and with the hexagon, as depicted in the frame 15.

In the FIG. 2, the windows 10 and 11 leave uncovered, and thus in view only the formulae (symbolized by a row of reference letters V, and by a'row of reference letters X, respectively) that allow the solution of problems involving a sphere, as depicted in the frame 16, and a triangular prism, as depicted in the frame 17.

By having the slides 6 and/or 7 suitably shifted, the windows 89 and 10-11 can obviously be brought into coincidence with other figures and through said windows, the formulae pertaining to other concerned geometric entities can be read.

The plate 1, the stationary component of device, is preferably formed with an extended edge 18 (shown by dash lines in the FIG. 1) in parallel relation with one of the major sides thereof, and whereon a millimeter, or otherwise graduated scale can be engraved.

Obviously, the depictions of geometric entities on the device may be in a number greater, or smaller, or partly different from that shown in the drawing, without departing from the innovating spirit of the invention.

Although the present invention has been described and illustrated in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit of invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention, as defined by the appended claims.

Having described my invention, I claim:

1. A device for quickly finding the main formulae for the solution of problems involving geometric entities, comprising a stationary elongated rectangular opaque plate having guides extending along and parallel to but spaced from each side of each longitudinal edge of the plate, a pair of elongated rectangular opaque slides parallel to each other and disposed on opposite sides of the plate one in each pair of said guides, each slide having two windows therein disposed on opposite sides of the longitudinal midline of the slide, the plate having continuously exposed representations of diiferent geometric entities along both longitudinal side edges thereof on both sides of the plate, the plate also having formulae for the solution of problems involving the same geometric entities disposed on opposite sides of the plate in a position to be covered by the associated said slide and exposed by a said window of UNITED STATES PATENTS 2,304,327 12/1942 Anderson 3575X FOREIGN PATENTS 1,122,563 5/1956 France 353l(5) WILLIAM H. GRIEB, Primary Examiner U.S. Cl. X.R. 3575 

